Sculptured Landscapes

Background:
Glacier National Park owes its spectacular scenery to the mountains and valleys that were carved by glaciers about 20,000 years ago. A glacier is a river of ice and rock debris that forms in the mountains from a massive buildup of snow. As the snow accumulates deeper and deeper, the weight causes the snow to compact and recrystallize into ice. Eventually the ice becomes so thick that gravity causes the accumulation to flow downhill in the form of a glacier. As it does so, the glacier erodes the underlying rock and carves features into the landscape that it flows over. Glacial erosion results in a spectacularly sculptured landscape that may contain some of the following landforms: cirques, striations and grooves, horns, arÍtes, cols, u-shaped valleys, hanging valleys, and moraines, drumlins, kettles, kames, and eskers.

In this activity, students will apply

cirque: the basin in which the ice and snow starts to accumulate and flow. After the glacier has melted, the basin can be seen as a huge semicircular ridge that may be up to 3,000 feet above the basin floor.

striations and grooves: scratches and gouges in rock caused by the abrasion of rock debris in the ice as the glacier moves across it.

horn: a steep pyramid-shaped mountain that is formed by the erosion of a ring of cirques juxtaposed next to each other.

arÍte: a jagged, steep ridge that is formed when two cirques erode into a ridge from opposite sides.

col: a gap in the ridge of an arÍte, formed by continued erosion by the cirque.

u-shaped valleys: The valley in which the glacier flows. As it flows the glacier erodes the valley walls, making them more rounded and u-shaped than steep, v-shaped river valleys.

hanging valley: a cliff at the end of a glacier tributary that was not carved as fast as the main valley it flows into. The main valley is carved much deeper than the valley of the tributary, leaving an escarpment between the two.

moraine: a ridge of glacial debris that is left behind after a glacier recedes.

drumlin: a teardrop-shaped hill composed of glacial debris in which a steep slope faces the uphill direction of the glacier and a gentle slope faces the downhill direction. They are formed by glaciers depositing rock debris as they move.

kettle: a depression in the till landscape left by a glacier after it recedes. It is formed by a block of ice that was separated from the glacier, buried by rock debris, and later melted.

kame: a steep-sided hill composed of stratified rock debris that is left by a receding glacier. They are formed when rock debris accumulates in the openings of stagnant ice.

esker: a winding, steep-sided ridge of debris formed by the deposits of streams running through tunnels under the glacier.

In this activity, students research glaciers, how they are formed, and what kind of landforms they carve out of the underlying rock. They will apply this knowledge to gain an appreciation for Glacier National Park and how the landscape has changed over time by natural forces.

Objectives:

Students will:

perform research on glaciers, glacial landforms, and Glacier National Park.

Standard 3:
People, Places, and Environment -- The study of people, places, and human-environment interactions assists learners as they create their spatial views and geographic perspectives of the world. Today's social, cultural, economic, and civic demands on individuals mean that students will need the knowledge, skills, and understanding to ask and answer questions such as: Where are things located? Why are they located where they are? What patterns are reflected in the groupings of things? What do we mean by region? How do landforms change?

Standard D: Earth and Space Science
All students should have an understanding the origin and evolution of the earth system

Materials:

White butcher paper

Color markers

Pencils, plain paper

Video camera and tapes

Great Lodges of the National Parks: Glacier Lodges , the following video clips appropriate to the lesson.

Start with: Set in the remote and wild northern Rockies of western Montana...End with: ...today on board Amtrak's Empire Builder.

Start with: Yet all the grandeur and amenities the Glacier Park Lodge has to offer, it's the Park's spectacular scenery that's the Park's real attraction.End with: I understand why people come to Glacier National Park, because I myself with my family have come her for 25 years. It is truly a beautiful place.

Start with: Leaving the lodge at Lake McDonald and the comforts of a front country hotel...End with: The colors are so unique that it's beautiful.

Start with: For years, the most spectacular vistas in GNP could only be enjoyed by those hardy souls...End with: It's a grand hotel in size, but it doesn't begin to compete with the backdrop of the glacial peaks behind it.

Start with: It's a great outdoor experience here at the lake.End with: And there's a good possibility that the viewer will either see a black bear or grizzly bear.

Preparation:
No special preparation is required.

Procedure:

Tell the class that they are about to view a video on Glacier National Park. Ask if anyone has ever been there. If someone has, ask them to describe the Park to the class. If no one has been there, ask what they know about the Park and glaciers in general, and then fill in the gaps. Tell them that as they watch the video clips, they are to pay particular attention to the natural features of the Park.

After viewing the video clips, ask them to sketch their impression of the scenery on a piece of paper. What stands out most in your mind?

Divide the class into groups of three. Explain that they are going to research the natural history and landforms of the Park. They will become TV news reporters doing a special interest story on places to go for a summer vacation. Each student will be a reporter and take turns speaking to the audience.

Each group of three will need to complete their research and write a script for their newscast. The following questions should be answered in their presentations: What is a glacier? What is it made of? How does a glacier form? How does it move? Where do glaciers exist today? What types of landforms are carved by glaciers and which of these are present at Glacier National Park? Their newscast should also include pictures to illustrate major points.

The groups will paint a backdrop for their newscast showing the scenery in the Park as if they were actually broadcasting from the Park.

When each group is ready, the teacher will videotape their newscasts in a quiet area, and then show all the newscasts to the class.

Assessment Suggestions:

Assessment may be based on the following rubric:

Knowledge of Glaciers Quality of Newscast Quality of Scenery Points

Presentation demonstrated a very good understanding of the material by being able to answer the required questions and giving supporting details. Students looked into the camera when speaking. They speak clearly, and the information is presented in a straightforward way. The backdrop was neat, creative, and added interest to the newscast. The representation of Glacier National Park was realistic.

Presentation demonstrated a fairly good understanding of the material but omitted important facts, details, or included inaccurate information. Students make some eye contact with the camera; most of the presentation is audible and is presented so that most of the information can be easily understood. The backdrop was an accurate representation, but the quality of the art did not add to the overall quality of the newscast.

Presentation provided a few facts about glaciers. Some statements were inaccurate. Students rarely look into the camera, speak too softly or too indistinct, and presentation is confusing to the audience. The representation was inaccurate and/or it was poorly executed.

Extensions:

Students try their hand at glacial erosion by freezing a mixture of pebbles and sand in a cup of water. After the water freezes, it is removed from the cup and rubbed against a piece of wood to observe the "erosion" of the wood by the ice mixture.

Research how near glaciers extended to their own local and if there is any glacial evidence in the area. If so, take a field trip to see it.

Research the location of major glaciers around the world, and draw their outlines on a map. Continue research by finding out what effects global warming will have on the polar regions and in turn, coastlines around the world.